Electrical connection device

ABSTRACT

The invention relates to a coaxial cable plug-in assembly for coaxial cables and including an electrical connection assembly. The electrical connection assembly can be connected to ground potential. The plug-in assembly includes two complementary parts. At least one of the plug-in assembly parts embraces an electrically insulating base member which is intended to accommodate a connecting device and which includes at least one through-penetrating hole adapted for coaction with a first subpart of a sleeve-like connecting device, and with a second subpart adapted for coaction with a coaxial cable whose screening conductor is intended to embrace the second subpart of the connecting device. The electrical connection assembly includes a spring-like collar which extends completely or partially around the second subpart of the connecting device for electrical and mechanical coaction between the subpart and the collar, and further includes a supportive part which coacts with the collar. The supportive part includes outer contact surfaces which are intended to abut the inner surface of a metal subpart with an adapted contact pressure, this inner surface being, in turn, related to ground potential.

TECHNICAL FIELD

The present invention is intended for application in an electric plug-inassembly, and then particularly, but not exclusively, in an electricplug-in assembly which includes electrical connection means adapted forcoaction with a plurality of coaxial cables, and is even more concernedwith a metallic electrical connection means which is included in thecable-related part of the plug-in assembly and which can be connected toan ground potential or ground reference.

It is fundamental to the invention that the electric plug-in assembly iscomprised of two complementary parts wherein at least one metalliccasing part or said one assembly part can be connected externally orinternally to ground potential and wherein at least one of said assemblyparts is divided into several parts, normally two parts.

The two complementary parts of the plug-in assembly are mutuallycoordinated so that they can be brought to a mutually coacting positionfor electrical and mechanical coaction between coaxial-cable adaptedelectrical connection means placed in respective assembly parts andcarrying a base member which can be embraced by the casing parts, or toa non-coacting position in which there is no electrical and mechanicalcoaction between coaxial-cable adapted electrical connection meansmounted in said complementary parts.

Electric plug-in assemblies of the kind to which the present inventionrefers thus comprise two complementary parts, and the invention findsparticular application when one of said parts is a circuit-boardassociated part and the other part is a cable-related part, wherein eachof said parts includes a metallic casing which is adapted to fullyembrace an electrically insulating base member into which there isinserted a plurality of electrically conductive coaxial contact devices.The metallic casing for the cable-related part may advantageouslycomprise two parts.

In other respects, the parts of the plug-in assembly are constructed sothat at least one of said parts will embrace a base member which is madeof an electrically insulating material and intended for one connectingdevice. The base member includes through-penetrating holes or channelswhich are adapted to hold or to coact with a first subpart of asleeve-like coaxial-cable adapted connecting device, wherein said firstsubpart is intended to coact with a first subpart of a complementaryconnecting device and with a second subpart which is adapted forcoaction with a stripped end of the coaxial cable, said cable end beingstripped so as to expose the central conductor of the cable and also toexpose an embracing screening conductor or screening stocking.

This coaction is achieved, among other things, by virtue of turning thescreening conductor around a support sleeve fitted over said secondsubpart, wherein the screening conductor is clamped firmly between thesecond subpart and the inner surface of an outer clamping sleeveprovided with electrical connection means, while using the supportsleeve.

The present invention can be applied to particular advantage in groundedcircuit board magazines, in which an external conductor and/orconductors is/are caused to coact with circuit-board related circuit,conductors and the like via electric connecting devices.

Magazines of the type intended here are adapted to handle in electroniccircuits information-carrying signals whose current and/or voltagepulses can have a frequency or bit rate that lies within the Gb/s range.

Electronic systems of the kind intended are encumbered with thedrawbacks that high frequency electromagnetic signals "leak" out asradio waves and the circuits become sensitive to such electromagneticdisturbance fields and therewith lose their ability to transmit theinformation-carrying signals correctly.

The invention is therefore intended from certain aspects to provide asystem in which all disturbing signal routes are carefully screened andrelated to ground potential.

The invention is also intended to overcome EMC-type disturbance fields(Electro Magnetic Compatibility).

DESCRIPTION OF THE BACKGROUND ART

Several different designs of electric plug-in assemblies in general andcoaxial cable plug-in assemblies in particular are known to the art.

At the high, and even higher, transmission speeds aforementioned, andwhen using coordinated contacts or contact devices in an electricplug-in assembly intended for coaxial cables, it is important thatsignal transmission can take place from a first coaxial cable to circuitboard components such that the central conductors of the coaxial cablesor the like obtain good contact with one another through the medium ofthe connecting devices of the plug-in assembly, although it is alsoimportant that the screening conductor of the coaxial cable is intactand connected directly to ground upstream of the system earth on thecircuit board, also through the medium of the plug-in assembly, so thatelectromagnetic disturbances will be passed to ground before manifestingas disturbances on the system ground.

In the case of coaxial cable plug-in assemblies, measures have alreadybeen taken to ensure that good electrical contact is achieved betweenthe central conductors and that good screening is also achieved throughthe plug-in assembly.

It is also known that when the transmission speed of the digitalizedsignals or current pulses, or the so-called bit rate, increases uptowards 150 Mb/s and higher, the plug-in assemblies used becomesensitive to occurrent disturbance voltages and that the transmittedcurrent pulses can become distorted to such an extent as to make itdifficult or impossible to understand the pulses.

Large voltages that occur on screening conductors have a highly negativeeffect in this respect.

It has been found practical to take measures for connecting thescreening conductor directly to ground potential at a point located somedistance upstream of the circuit board.

It is also known (U.S. Pat. No. 4,820,201) to connect the screeningconductor of a coaxial cable to a metallic plug-in-assembly casing withthe aid of a metal plate.

It is also known (U.S. Pat. No. 3,670,292) to use a foil having innerand outer resilient tabs for grounding purposes.

SUMMARY OF THE INVENTION

Technical Problems

When considering the present standpoint of techniques as describedabove, it will be seen that a technical problem resides in providing inan electric plug-in assembly intended for a plurality of coaxial cableselectrical connection means which can be connected to ground potentialand which can be readily enclosed in the cable-related metal casing partof the assembly and be able to establish contact with all screeningconductors and sleeves and also to coact with the inner metal surfacesof the casing parts, wherewith said casing parts can be connectedexternally directly to ground potential.

It will be seen that a further technical problem is one of giving theelectrical connection means a form which will not only conform readilyto the interior space of one cable-related casing part of the plug-inassembly but which will provide a saving in material at the same time.

It will also be seen that a technical problem resides in providing aelectrical connection means whose form and structure are well suited forapplication as a separate material-lean unit within the casing partwhile still providing good electrical contact with each exposed subpartof the connecting devices so as to provide good electrical springcontact and a mechanically stable connection between each subpart andthe metallic casing part or parts.

Another technical problem is one of realizing the significance ofallowing the electrical connection means to embrace and coact with anouter surface of a sleeve which belongs to a coaxial contact devicethrough the medium of resilient tabs or tongues, said sleeve beingcaused to clamp the screening conductor firmly around the sleeve-likesubpart (second subpart) of the connecting device and/or adjacent saidsleeve.

It will also be seen that a further technical problem is one ofrealizing the significance of and the prerequisites for providing theelectrical connection means with four spring-related tabs or tongueswhich extend completely or partially around the second subpart of theconnecting device and/or sleeve, so as to provide electric andmechanical coaction between a subpart and the sleeve with the aid ofsaid tabs or tongues, and a supportive part which coacts with the tabsor tongues and integrated therewith.

It will also be seen that a technical problem is one of realizing thesignificance of distributing ground-potential related contact points ofthe electrical connection means uniformly around the earth-relatedscreening conductor or stocking of the coaxial cable.

It will also be seen that a technical problem resides in realizing withregard to a desired ground connection those advantages that are affordedwhen said supportive part is provided with a small number of sparselydistributed outer contact surfaces and when the contact surfaces areadapted and dimensioned to abut the inner surfaces of opposing metalparts with a sufficient and adapted contact pressure, and to provideexternal means for connecting said parts to ground potential.

It will also be seen that a technical problem resides in providing amaterial-lean electrical connection means which is able to coact witheach coaxial-cable related connecting device inserted into a basemember, even when the number of holes in the base member exceeds thenumber of connecting devices to be accommodated by said holes.

It will also be seen that a technical problem resides in realizing thesignificance of allowing the spring-like tabs to be formed by fourcorner-related resilient projections which extend from said supportivepart, such that the length and spring-properties of the tabs will permitsaid inner tongues and the second subpart of the connecting device andsaid supportive part to take mutually different positions, so as tocreate therewith conditions which will enable each sleeve-likeconnecting device inserted into a hole in the base member to adapt togood coaction with each corresponding and complementary connectingdevice.

Another technical problem resides in the significance of giving saidsupportive part a right-angled shape and to adapt its outer dimensionsfor enclosure in one of said metal parts.

It will also be seen that another technical problem resides in realizingthe significance of providing the supportive part with requisitediscrete contact surfaces, a number of outer surfaces which face towardsthe inner surfaces of the metal parts, and four and four facing towardsan adjacent coupling device.

It then becomes a technical problem to realize the significance ofproviding the supportive part with first category contact surfaces,namely four and four corner-related surfaces for each connecting deviceand located outermost on contact springs that extend obliquely to oneanother.

A further technical problem is one of providing with simple meansconditions whereby the requisite contact surfaces will be formed by thetips of four elongated, narrow resilient metal parts or tabs, with thetips extending obliquely but essentially towards one another.

It will also be seen that a technical problem resides in realizing thesignificance of locating said contact surfaces in a first plane whichextends adjacent a resilient section having said narrow, elongatedresilient parts.

It will also be seen that a further technical problem is one ofrealizing the significance of providing a construction in which a secondcategory of contact surfaces are formed in a second plane which extendsparallel with said first plane.

Another technical problem is one of realizing that electrical connectionmeans of the aforesaid kind can use a base member which includes aplurality of mutually parallel holes or channels, with said holes orchannels disposed in rows and columns, such as two rows and threecolumns.

It will also be seen that in this technical field and in the case of anelectrical connection means of the kind defined in the introduction afurther technical problem resides in realizing the significance ofallowing one subpart of each connecting device to be mounted in itsrespective hole in the base member such that said subpart can be tiltedor tipped therein, and to permit an assigned pivot axle or fulcrum pointto be moved to or in the proximity of said electrical connection means.

It will also be seen that a technical problem resides in realizing thesignificance of giving the connecting-means supportive part arectangular outer shape which is adapted to enable supportive partshaving edge-orientated discrete, resilient parts to abut a metalliccasing part.

It will also be seen that a technical problem resides in realizing themanufacturing/technical and use/technical advantages that are affordedwhen the outer resilient parts are comprised of parallel-relatedprojections.

It will also be seen that a technical problem resides in providingelectrical connection means of the kind defined in the introduction andintended for the aforesaid application which have a material thicknessof between 0.07-0.25 mm, and therewith to realize the significance ofchoosing stainless steel as the material used.

A further technical problem is one of realizing that said electricalconnection means shall be orientated adjacent the base member and thatthe inner resilient sections shall be inclined towards the connectingdevice and that said edge-orientated outer resilient parts shall beinclined towards the metallic casing in one and the same direction fromsaid supportive part.

Solution

With the intention of solving one or more of the aforesaid technicalproblems, the present invention takes as its starting point a electricalconnection means which is included in a cable-related electrical plug-inassembly for one or more coaxial cables, wherein the screening conductorof said one or more coaxial cables shall be connected to ground, andwherein the plug-in assembly has the features defined in theintroduction.

A coupling means according to the invention is based on a plurality ofspring-like tabs which surround, completely or partially, a secondsubpart or sleeve of the connecting device, such as to achieveelectrical and mechanical coaction between said subpart or sleeve andsaid tabs, and also on a supportive part which coacts with the tabs andis integral therewith.

The supportive part has obliquely and outwardly facing outer contactsurfaces, which are adapted to abut the inner surfaces of opposing partswith an adapted contact pressure when the two parts of the casing partmutually coact, said casing parts being, in turn, ground-potentialrelated.

It is proposed in accordance with the invention that the connectingdevice will have a specific form in which said inner tabs arecorner-related in relation to an otherwise square aperture andorientated in a direction towards a centre line of said aperture, andthat narrow supportive parts delimit one aperture from an adjacentaperture.

According to proposed embodiments that lie within the scope of theinventive concept, the assembly includes an insulating base member whichincludes a plurality of holes or channels, wherein each connectingdevice inserted into a respective hole coacts with mutually the sameground-related connecting means.

According to one embodiment, the spring-like tabs are formed byelongated resilient, or spring-like, sections that extend from saidelectrical connection means supportive part.

It is also proposed that the connecting-means supportive part has agenerally right-angled outer shape.

According to one embodiment, the supportive part includes tongue-relatedcontact surfaces which are directed obliquely towards one another, andthe contact surfaces are formed at the tips or points of four elongated,narrow resilient parts and disposed uniformly around their respectiveconnecting devices.

The aforesaid contact surfaces will preferably be located within a firstplane of the elongated resilient parts and each is located outermost ona resilient section.

The resilient sections are disposed in a second plane.

It is also proposed that one subpart of the connecting device will bemounted or received in a respective hole in the base member in a mannerwhich will allow the subpart to tilt or to tip to some extent.

According to one embodiment, the connecting-means supportive part has asquare or rectangular shape and is adapted to abut opposing metalliccasing parts through the medium of edge-orientated, outer resilientparts.

The resilient parts are advantageously comprised of parallel, relatedprojections.

The electrical connection means may be relatively thin and will normallyhave a thickness or between 0.07-0.25 mm.

It is also proposed that the electrical connection means are orientatedadjacent the base member and that said resilient sections and saidedge-orientated resilient parts are arranged to slope slightly in thesame direction from said supportive part and towards the base member.

Advantages

Those advantages that are primarily afforded by an electrical connectionmeans that is constructed in accordance with the present invention andincluded in a cable-related electric plug-in assembly intended toaccommodate a plurality of coaxial cables reside in the provision ofconditions whereby there is obtained through the medium of amaterial-lean electrical connection means direct electrical andmechanical contact and direct coaction between the screening conductoror screening stocking of respective coaxial cables and at least onemetal casing Dart belonging to the electric plug-in assembly andconnecting directly or indirectly to ground, thereby to createconditions for conducting away disturbance voltages and electromagneticdisturbance fields that are liable to seriously jeopardize detection ofinformation-carrying voltage pulses that are transmitted at hightransmission speeds on the conductors of the coaxial cables.

A particular advantage resides in the possibilities of creatingsatisfactory conditions for conducting EMC disturbances to groundpotential prior to said disturbances occurring on the system ground.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of a cable-related electric plug-in assembly foraccommodating a number of coaxial cables, and two embodiments ofelectrical connection means used with said assembly in accordance withthe invention will now be described in more detail with reference to theaccompanying drawings, in which

FIG. 1 is a perspective exploded view of an assembled printed circuitboard pressed firmly into a board-receiving frame, where an aperturedrail or bar is connected to ground potential, and where each plug-inassembly comprises two complementary parts, of which one is shown spacedoutside the rail;

FIG. 2 is an exploded perspective view of a base member which can beinserted into a part of the plug-in assembly shown in FIG. 1 and whichincludes two times three holes for receiving coaxial-cable typeconnecting devices and which is provided with electrical connectionmeans according to the invention;

FIG. 3 is a side view of the electrical connection means shown in FIG.2;

FIG. 4 illustrates the electrical connection means from above;

FIG. 5 is an enlarged perspective view of the coupling means shown inFIG. 2;

FIG. 6 is a side view of the coupling means, namely the collar-like partthat is intended to coact with an electrically conductive, groundedsleeve for the connecting device;

FIG. 7 is a side view of a second embodiment of a electrical connectionmeans;

FIG. 8 is another side view of the electrical connection means shown inFIG. 7;

FIG. 9 shows the electrical connection means of FIG. 7 from above; and

FIG. 10 is a side view of a connecting device coupled to a coaxialcable.

DESCRIPTION OF EMBODIMENTS AT PRESENT PREFERRED

The present invention is thus concerned with an electric plug-inassembly 1 for a coaxial cable 2, and more particularly to acoaxial-cable related connecting part of the assembly 1.

The plug-in assembly 1 is comprised of two complementary parts 1a, 1b,of which at least one part, 1b, can be connected directly to earthpotential through the medium of a magazine.

The illustrated electric plug-in assembly 1 includes a coaxial-cablerelated part 1a and a circuit-board related part 1b, the part 1b beingshown fixedly connected to a circuit board K.

In the illustrated embodiment, the part 1b is connected to a metallic,ground-potential related rail 3, said part 1b being connected to therail 3 through the medium of an electrically conductive springarrangement 3a, the upper part, or alternatively the lower part, of therail 3 being connected electrically to ground potential or to an groundreference through the medium of screw connections.

The cable-related part 1a of the plug-in assembly includes an outer,two-part metallic casing including the parts 1a' and 1a" which carry anelectrically insulating base member 4.

The base member 4 includes holes or channels (two times three) of whichone hole, is referenced 4a.

The hole or channel 4a is intended to secure a connecting device 5 whichextends through a electrical connection means 6 in accordance with theinvention.

The two complementary assembly parts 1a, 1b are so mutually coordinatedas to enable said parts to be brought to a mutually coacting position(not shown in FIG. 1) for electrical and mechanical coaction between acoaxial-cable related connecting device 5 placed between said parts, orto be brought to a non-coacting position in which there is no electricaland mechanical coaction between the coaxial-cable related connectingdevice positioned between said parts.

For the sake of clarity, the connecting devices intended for the part 1bhave not been shown in the Figure.

The casing of at least one of said assembly parts, namely the part 1a,embraces an electrically insulating base member 4 which is intended toaccommodate a plurality of connecting devices.

Each of said channels or holes, such as the hole 4a, is adapted forcoaction with a first subpart 5a of a sleeve-like connecting device 5,and with a second subpart 5b adapted for coaction with a coaxial cable 2whose screening conductor 2a is intended to be capable to embracing thesecond subpart 5b.

When a stripped coaxial cable 2 is inserted into a hole 5c, with thecentral conductor 2b adapted to coact with the first subpart 5a, thescreening conductor 2a can be threaded over a sleeve inserted into thesubpart 5b and the part 5d secured over the subpart 5b with thescreening conductor 2a held therebetween, e.g. with the aid of acrimping tool.

The base member 4 will thus be accommodated within the part 1a' and thepart 1a is held to the part 1b in an assembled state with the aid ofscrews 7, 7a.

The part 1a" can be secured to the part 1a' with the aid of screws 8 and8a, in a known manner.

The inventive electrical connection means 6 includes a spring-relatedtab-like collar 11 which extends completely around the second subpart 5bof the connecting device, to obtain electrical and mechanical coactionbetween said subpart 5b and said collar 11.

The electrical connection means 6 also includes a supportive part 13which coacts with the collar 11 and which may be integral therewith.

The supportive part 13 is rectangular in shape and includes along onelong edge four outer resilient or springy contact surfaces, of which oneis referenced 14a, and along the other edge four resilient or springycontact surfaces which are parallel with the aforesaid contact surfacesand of which one is referenced 15a. The contact surfaces are adapted toabut inner, opposing metal surfaces on the metal part 1a' or the metalpart 1a" with an adapted contact pressure.

As before mentioned, the base member 4 may include a plurality of holes,in the illustrated embodiment 6 holes, and that each connecting deviceinserted into a respective hole is able to coact with the electricalconnection means, shown in FIGS. 3-6.

The resilient or springy tab-like collar 11 is formed by resilient orspringy sections 16 that extend from the part 13 supporting saidelectrical connection means 6.

The supportive part 13 has a right-angled external shape and includesthree mutually parallel side members 13a, 13b and 13c, and four mutuallyparallel side members 13d, 13e, 13f and 13g which extend perpendicularlyto the first-mentioned side members. The side members thus define in thesupportive part 13 six square apertures of which each presents fourouter collar-related contact surfaces 16a, 16b, 16c, 16d which areinclined obliquely in relation to one another and which are formed atthe tips of four elongated resilient parts 17a, 17b, 17c and 17d whosebases coact with the corners of said members 13b, 13c, 13f, 13g.

The contact surfaces 16a, 16b, 16c and 16d are located within a firstplane "A" which extends adjacent resilient or springy sections on whichsaid elongated, resilient or springy contact surfaces 16a, 16b, 16c and16d are provided.

The resilient sections are disposed in a second plane "B" which extendsslightly sideways of the first plane but parallel therewith.

It is important to the present invention that one subpart 5a of theconnecting device can be secured in the hole 4a in the base member 4 ina manner which will enable said subpart to be tilted or tipped in orderto compensate for a poor fit. To this end, the resilient sections16a-16d are orientated so that the sleeve 5a with an applied tab-likecollar 11 is able to move without resulting in any appreciable movementof the supportive part 13.

The connection means 6 may have a material thickness of between0.07-0.25 mm, preferably about 0.15 mm, and may be made of stainlesssteel.

When the parts 1a' and 1a" coact within a part 1a, the contact surfaces14a, 15a, which extend obliquely towards one another, will lie againstthe inner opposing surfaces of one or both casing parts with a givencontact pressure.

FIGS. 7-9 illustrate a second embodiment in which the contact surfaces15a, 14a have longer lengths.

The part 6 of both embodiments shall be made of stainless steel andgilded so that the contact surfaces 16a, 16b, 16c and 16d will becomprised of gold and capable of abutting a gilded contact point 5fadjacent a collar 5g, as shown in FIG. 10.

The contact surfaces 14a, 15a are tin-coated, as they are intended toabut tin-coated casing parts.

FIG. 10 illustrates a connecting device 5 whose subpart 5a is insertedthrough a supportive part 13 to an extent at which the collar 5g haspassed the contact surfaces 16a-16d, which therewith snap-in behind thecollar 5g, so that said contact surfaces will lie against the sleeve 5with the requisite contact pressure.

In order to achieve the aforesaid tippable or tiltable attachment, thefulcrum or pivot point will preferably lie around the collar 5g, andmore preferably at the point referenced 5f.

It will be understood that the invention is not restricted to theaforedescribed and illustrated exemplifying embodiments thereof and thatmodifications can be made within the scope of the inventive concept asdefined in the following claims.

We claim:
 1. An electric coaxial cable plug-in assembly havingelectrical connection means which can be connected to earth potential,comprising:two or more connecting devices, each of the two or moreconnecting devices being adapted to receive a coaxial cable; first andsecond complementary parts, the first and second complementary partsforming a structure in which the two or more connecting devices arereceived, the first part being connectable to ground potential and thesecond part being divided into a plurality of parts, the first andsecond parts being movable between a position for electrical andmechanical coaction between the two or more connecting devices and thefirst part and a position in which no electrical and mechanical coactionexists between the first part and the two or more connecting devices,the second part embracing an electrically insulating base member thatreceives the two or more connecting devices, the base member includingtwo or more through-penetrating holes, each hole coacting with a firstsubpart of a respective one of the two or more connecting devices andcoacting with a second subpart of the respective one of the two or moreconnecting devices, the second subpart being adapted for coaction with acoaxial cable having a screening conductor for embracing the secondsubpart; and electrical connection means including a supportive part inwhich two or more square-shaped apertures are formed, each of the two ormore apertures being delimited from an adjacent aperture of the two ormore apertures by rectangular side members of the supportive part, andeach of the two or more apertures extending at least partially around asecond subpart of a corresponding one of the two or more connectingdevices, the electrical connection means further including four innertabs corresponding to each of the two or more apertures, each inner tabextending from a corner of a corresponding one of the two or moreapertures toward a center of the corresponding one of the two or moreapertures, the supportive part including one or more outer contactsurfaces for abutting under pressure against the second part; whereineach first subpart of each connecting device of the two or moreconnecting devices is secured in a corresponding hole of the two or moreholes of the base member such that the first subpart is tiltablerelative to the base member to compensate for a poor fit in the basemember.
 2. A plug-in assembly according to claim 1, wherein each innertab includes a resilient section that is oriented so that the firstsubpart is movable through the corresponding aperture of the two or moreapertures relative to the supportive part.
 3. A plug-in assemblyaccording to claim 1, wherein each inner tab includes an elongatedresilient section.
 4. A plug-in assembly according to claim 2, wherein,for each inner tab, a contact surface for contacting the first subpartof the corresponding contact device is provided at a tip of theresilient section of the inner tab.
 5. A plug-in assembly according toclaim 4, wherein the contact surfaces of the inner tabs are disposedwithin a first plane parallel to a plane of the side members of thesupportive part.
 6. A plug-in assembly according to claim 5, wherein theside members of the supportive part are disposed in a second planedifferent from the first plane.
 7. A plug-in assembly according to claim1, wherein the supportive part is between 0.07-0.25 mm thick.